A 3D semiconductor device, the device comprising: a first level comprising a first single crystal layer, said first level comprising first transistors, wherein each of said first transistors comprises a single crystal channel; first metal layers interconnecting at least said first transistors; a second metal layer overlaying said first metal layers; and a second level comprising a second single crystal layer, said second level comprising second transistors, wherein said second level overlays said first level, wherein at least one of said second transistors comprises a gate all around structure, wherein said second level is directly bonded to said first level, and wherein said bonded comprises direct oxide to oxide bonds.

A semiconductor device including: a first silicon layer including a first single crystal silicon and a plurality of first transistors; a first metal layer disposed over the first silicon layer; a second metal layer disposed over the first metal layer; a third metal layer disposed over the second metal layer; a second level including a plurality of second transistors, the second level disposed over the third metal layer; a fourth metal layer disposed over the second level; a fifth metal layer disposed over the fourth metal layer, where the fourth metal layer is aligned to first metal layer with a less than 40 nm alignment error; and a via disposed through the second level, where each of the second transistors includes a metal gate, and where a typical thickness of the second metal layer is greater than a typical thickness of the third metal layer by at least 50%.

A 3D integrated circuit, the circuit including: a first level including a first wafer, the first wafer including a first crystalline substrate, a plurality of first transistors, and first copper interconnecting layers, where the first copper interconnecting layers at least interconnect the plurality of first transistors; and a second level including a second wafer, the second wafer including a second crystalline substrate, a plurality of second transistors, and second copper interconnecting layers, where the second copper interconnecting layers at least interconnect the plurality of second transistors, where the second level is bonded to the first level, where the bonded includes metal to metal bonding, where the bonded includes oxide to oxide bonding, and where at least one of the second transistors include a replacement gate.

A 3D semiconductor device with a built-in-test-circuit (BIST), the device comprising: a first single-crystal substrate with a plurality of logic circuits disposed therein, wherein said first single-crystal substrate comprises a device area, wherein said plurality of logic circuits comprise at least a first interconnected array of processor logic, wherein said plurality of logic circuits comprise at least a second interconnected set of circuits comprising a first logic circuit, a second logic circuit, and a third logic circuit, wherein said second interconnected set of logic circuits further comprise switching circuits that support replacing said first logic circuit and/or said second logic circuit with said third logic circuit; and said built-in-test-circuit (BIST), wherein said first logic circuit is testable by said built-in-test-circuit (BIST), and wherein said second logic circuit is testable by said built-in-test-circuit (BIST).

A semiconductor device including: a first silicon level including a first single crystal silicon layer and a plurality of first transistors; a first metal layer disposed over the first silicon level; a second metal layer disposed over the first metal layer; a third metal layer disposed over the second metal layer; a second level including a plurality of second transistors, the second level disposed over the third metal layer; a fourth metal layer disposed over the second level; a fifth metal layer disposed over the fourth metal layer, where the fourth metal layer is aligned to the first metal layer with a less than 40 nm alignment error; a via disposed through the second level, where each of the second transistors includes a metal gate, where a typical thickness of the second metal layer is greater than a typical thickness of the third metal layer by at least 50%.

An integrated circuit which enables lower cost yet provides superior performance compared to standard silicon integrated circuits by utilizing thin film transistors (TFTs) fabricated in BEOL. Improved memory circuits are enabled by utilizing TFTs to improve density and access in a three dimensional circuit design which minimizes die area. Improved I/O is enabled by eliminating the area on the surface of the semiconductor dedicated to I/O and allowing many times the number of I/O available. Improved speed and lower power are also enabled by the shortened metal routing lines and reducing leakage.

A semiconductor device, including: a first memory cell including a first transistor; a second memory cell including a second transistor, where the second transistor overlays the first transistor and the second transistor self-aligned to the first transistor; and a plurality of junctionless transistors, where at least one of the junctionless transistors controls access to at least one of the memory cells.

A method for producing a 3D semiconductor device including: providing a first level including a first single crystal layer; forming a first metal layer on top of first level; forming a second metal layer on top of the first metal layer; forming at least one second level above the second metal layer; performing a first lithography step on the second level; forming a third level on top of the second level; performing a second lithography step on the third level; perform processing steps to form first memory cells within the second level and second memory cells within the third level, where first memory cells include at least one second transistor, and the second memory cells include at least one third transistor; and deposit a gate electrode for the second and the third transistors simultaneously.

A 3D semiconductor device including: a first single crystal layer including a plurality of first transistors and a first metal layer, where a second metal layer is disposed atop the first metal layer; a plurality of logic gates including the first metal layer and first transistors; a plurality of second transistors disposed atop the second metal layer; a plurality of third transistors disposed atop the second transistors; a top metal layer disposed atop the third transistors; and a memory array including word-lines, where the memory array includes at least four memory mini arrays, where each of the mini arrays includes at least two rows by two columns of memory cells, where each memory cell includes one of the second transistors or one of the third transistors, and where one of the second transistors is self-aligned to one of the third transistors, being processed following a same lithography step.

A 3D semiconductor device, the device including: a first level including a first single crystal layer and first single crystal transistors; a first metal layer; a second metal layer disposed atop the first metal layer; second transistors disposed atop of the second metal layer; third transistors disposed atop of the second transistors, where at least one of the third transistors includes at least one replacement gate, being processed to replace a non-metal gate material with a metal based gate, and where a distance from at least one of the third transistors to at least one of the first transistors is less than 2 microns.